In some cases, plural heat receivers are arranged in series on a path through which a refrigerant flows. Such a heat receiver into which the refrigerant flows receives heat from a heat-generating part. A technique related to such a heat receiver is disclosed in Japanese Patent Application Publication Nos. 2007-324498, 05-160310, 2007-272294, and 2009-075801.
The refrigerant discharged from the heat receiver on the upstream side flows into the heat receiver on the downstream side. Therefore, the refrigerant that has already received heat from the heat receiver on the upstream side flows into the heat receiver on the downstream side. Thus, as compared with the heat receiving efficiency of the heat receiver on the upstream side, the heat receiving efficiency of the heat receiver on the downstream side might be low.